Daredevil Nik Wallenda took reality television to a new level of risk with Discovery Channel’s live broadcast of two tightrope walks — one blindfolded and the other at a steep incline — between two Chicago skyscrapers 61 stories above the ground on Sunday.

Wallenda walked the two different spans between Chicago skyscrapers without a net or harness, with the network prepared to cut away to prevent viewers from having to witness any fall. The live event was broadcast on a 10-second delay.

It was a big risk for the network, which is looking to lure in viewers with a stunt that will defy delayed viewing. They’re also hoping viewers will come back in numbers similar to what they saw for Wallenda’s last live stunt, when 13 million viewers watched him cross the Grand Canyon in June 2013.

Wallenda tackled one walk on a 19-degree incline (it was increased from 15 degrees at the last minute), scaling eight stories by the time he reached the other end. For the other walk, he was blindfolded. Taking place after dark and with Chicago’s infamous winds in the mix, Wallenda indicated this would be his most dangerous walk yet.

Daredevil stunts run in the family, with Nik the seventh generation Wallenda to risk his life in such a manner. In 1978, his great-grandfather, Karl Wallenda, died attempting to walk between two buildings in Puerto Rico.

On Sunday, Wallenda completed the first of his two walks, scaling the incline wire. He chatted throughout, keeping viewers abreast of what he was experiencing. There was some concern about the movement of the wire at one point. Wallenda indicated he’d been planning to take a selfie mid-walk — 630 feet above the Chicago River — but changed his mind and stuck with his steady pace.

The second part of his walk was even more challenging, although much shorter. His father had to become his eyes, via a bullhorn, as Nik was blindfolded for the duration. He made short work of it, however, embracing his dad once both stunts were completed.

“Skyscraper Live with Nik Wallenda” aired live across the United States and in more than 220 countries and territories. The Discovery Channel event was hosted by NBC News’ Willie Geist and Natalie Morales, and The Weather Channel’s Jim Cantore.